Steps to reproduce the issue:
1. Create a jcr:content resource with the property sling:alias set to 'foo' (e.g. at /content/test/page1/jcr:content)
2. Create another jcr:content resource withe the property sling:alias to 'bar' at the same parent resource (e.g. at /content/test/page2/jcr:content)
4. Make sure that the 'Optimize alias resolution' feature of the JCR Resource Resolver Factory is enabled
=> As expected a request to /content/test/foo and /content/test/bar is getting mapped to page1 and page2
5. Create a child content resource at /content/test/page2/jcr:content/title with some example property
6. Delete the child content resource from step 5.
/content/test/foo and /content/test/bar are still mapped to /content/test/page1 and /content/test/page2
Only the map entry for /content/test/foo can still be mapped to page1, all other map entries of the same parent level at /content/test are removed.